This document discloses a method and apparatus for image encoding/decoding which support multiple layers. The method for image decoding comprises analyzing a video parameter set (VPS) extension for layer dependency on a current layer, analyzing slices for layer dependency on a current slice by determining whether not to apply layer dependency to the current slice or to apply new layer dependency to the current slice, the new layer dependency determining within a range of layer dependency analyzed from the VPS extension, and constructing a reference picture list about the current layer based on at least one of layer dependency analyzed from the VPS extension and layer dependency analyzed from the slice.
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1. A method for image decoding that supports multiple layers performed by an image decoding apparatus, the method comprising: analyzing a first layer dependency on a current layer based on a video parameter set (VPS) extension; analyzing a second layer dependency on a current slice based on information encoded in a slice unit, wherein analyzing the second layer dependency on the current slice comprises determining whether the current slice uses the first layer dependency of the VPS extension or the second layer dependency of the slice unit, obtaining, in response to a determination that the current slice uses the second layer dependency of the slice unit, first information indicating the number of reference pictures for inter-layer prediction of the current slice and second information identifying reference layers to which the reference pictures belong, the first information and the second information being signaled in the slice unit, and analyzing the second layer dependency on the current slice based on the first information and the second information; and constructing a reference picture list for the current slice based on at least one of the first layer dependency on the current layer and the second layer dependency on the current slice.
An image decoding method for multi-layered video streams analyzes layer dependencies from two sources to create a reference picture list. First, it analyzes a Video Parameter Set (VPS) extension to determine the default layer dependency for a current layer. Second, for each slice, the method checks if it should use the VPS-defined dependency or override it with slice-specific dependencies signaled within the slice data. If the slice uses its own dependency, the decoder reads information specifying the number of reference pictures and the IDs of the reference layers they belong to. The final reference picture list is built using either the VPS-defined dependencies or the slice-specific dependencies.
2. The method of claim 1 , wherein the reference picture list includes a long-term reference picture set, a short-term reference picture set and the reference layer set, and the reference layer set includes a picture of a reference layer having the same Picture Order Count (POC) as a current picture of the current layer.
The image decoding method from the previous claim constructs a reference picture list containing three sets: a long-term reference picture set, a short-term reference picture set, and a reference layer set. The reference layer set includes pictures from reference layers that have the same Picture Order Count (POC) value as the current picture being decoded. This ensures that the decoder can correctly correlate and utilize information from other layers that correspond to the current frame in the multi-layered video stream. The long-term and short-term reference picture sets contain temporally related frames within the same layer.
3. A method for image encoding that supports multiple layers performed by an image encoding apparatus, the method comprising: encoding a first layer dependency on a current layer using a video parameter set (VPS) extension by determining the first layer dependency on the current layer; encoding a second layer dependency on a current slice in a slice unit by determining the second layer dependency on the current slice, wherein encoding the second layer dependency on the current slice comprises determining whether the current slice uses the first layer dependency of the VPS extension or the second layer dependency of the slice unit, determining, in response to a determination that the current slice uses the second layer dependency of the slice unit, the number of reference pictures for inter-layer prediction of the current slice and reference layers referenced by the current slice, the number of reference pictures for inter-layer prediction and the reference layers being determined in the slice unit, and encoding the second layer dependency on the current slice based on the number of reference pictures for inter-layer prediction and the reference layers; and constructing a reference picture list for the current slice based on at least one of the first layer dependency on the current layer and the second layer dependency on the current slice.
An image encoding method for multi-layered video streams determines layer dependencies and encodes them for the decoder. It encodes a default layer dependency for each layer in the Video Parameter Set (VPS) extension. For each slice, the encoder decides whether to use this VPS-defined dependency or specify a slice-specific dependency within the slice data. If a slice-specific dependency is used, the encoder determines the number of reference pictures for inter-layer prediction and the IDs of the reference layers used by the current slice and encodes this information into the slice unit. Finally, it constructs a reference picture list based on either the VPS-defined dependency or the slice-specific dependency.
4. The method of claim 3 , wherein the reference picture list includes a long-term reference picture set, a short-term reference picture set and the reference layer set, and the reference layer set includes a picture of a reference layer having the same Picture Order Count (POC) as a current picture of the current layer.
The image encoding method from the previous claim constructs a reference picture list including a long-term reference picture set, a short-term reference picture set, and a reference layer set. The reference layer set includes pictures from reference layers having the same Picture Order Count (POC) as the current picture of the current layer. This ensures temporal alignment for inter-layer prediction. The encoder includes information allowing the decoder to reconstruct this reference picture list.
5. An apparatus for image decoding that supports multiple layers, the apparatus comprising: a decoder configured to analyze a first layer dependency on a current layer based on a video parameter set (VPS) extension, determine whether the current slice uses the first layer dependency of the VPS extension or a second layer dependency of a slice unit, obtain, in response to a determination that the current slice uses the second layer dependency of the slice unit, first information indicating the number of reference pictures for inter-layer prediction of the current slice and second information identifying reference layers referenced by the current slice, the first information and the second information being signaled in the slice unit, and analyze the second layer dependency on the current slice based on the first information and the second information; and a predictor configured to construct a reference picture list for the current slice based on at least one of the first layer dependency on the current layer and the second layer dependency on the current slice, and perform prediction based on the reference picture list.
An image decoding apparatus for multi-layered video streams includes a decoder and a predictor. The decoder analyzes layer dependencies by examining a Video Parameter Set (VPS) extension to determine the default layer dependency. It checks each slice to determine if it uses the VPS-defined dependency or a slice-specific dependency. If slice-specific dependency is used, the decoder extracts the number of reference pictures and the reference layer IDs signaled within the slice data. The predictor constructs a reference picture list based on either the VPS-defined dependency or the slice-specific dependency. The predictor then uses this reference picture list to perform inter-layer prediction, decoding the current image.
6. A non-transitory computer-readable medium storing a bitstream, wherein the bitstream is generated by a method for image encoding that supports multiple layers performed by an image encoding apparatus, the method comprising: encoding a first layer dependency on a current layer using a video parameter set (VPS) extension by determining the first layer dependency on the current layer; encoding a second layer dependency on a current slice in a slice unit by determining the second layer dependency on the current slice, wherein encoding the second layer dependency on the current slice comprises: determining whether the current slice uses the first layer dependency of the VPS extension or the second layer dependency of the slice unit; determining, in response to a determination that the current slice uses the second layer dependency of the slice unit, the number of reference pictures for inter-layer prediction of the current slice and reference layers referenced by the current slice, the number of reference pictures for inter-layer prediction and the reference layers being determined in the slice unit; and encoding the second layer dependency on the current slice based on the number of reference pictures for inter-layer prediction and the reference layers; and constructing a reference picture list for the current slice based on at least one of the first layer dependency on the current layer and the second layer dependency on the current slice.
A non-transitory computer-readable medium stores a bitstream generated by a multi-layer image encoding process. The encoding process includes encoding a first layer dependency for each layer using a Video Parameter Set (VPS) extension. It then encodes a second layer dependency for each slice, determining whether each slice uses the VPS-defined dependency or a slice-specific dependency signaled within the slice unit. If the slice uses its own dependency, the encoder determines and encodes the number of reference pictures for inter-layer prediction and the reference layers used, signaling these values in the slice unit. A reference picture list is constructed based on the first or second layer dependency and is used for encoding prediction residuals and motion vectors.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
December 27, 2013
December 19, 2017
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